In the past the deposition of adhesives, sealants, lubricants and the like has been plagued by many problems. In the absence of any type of a mechanical dispenser, the application of such materials is more often than not a messy and inaccurate operation. Frequently, an expensive substance is haphazardly applied, wasting valuable material and generating unnecessary clean-up costs. Even the use of one of the many types of dispensers heretofore known to those skilled in the art has failed to eliminate all of the problems. While many of these dispensing devices may dispense certain materials accurately, they are still not capable of producing uniform shots of a flowable material, the viscosity of which is subject to change, a common phenomenon in flowable materials such as epoxy resin adhesives. Nor can they accommodate a variety of materials having a wide range of viscosities. Conventional dispensers may reduce the wastage of material, but the necessary periodic readjustments of these dispensing devices produces undesirable "down-time", crating inefficiencies in a common production process situation. Maintenance and changeover of materials is also commonly time consuming and costly. Furthermore, many of the dispenser heretofore available are susceptible to undesirable dripping of material from the dispensing nozzle after dispensing the desired amount of material.
It would therefore be desirable to have an improved flowable material dispenser that operates with continual accuracy despite changing viscosities of materials, accommodates a wide range of viscosities, reduces maintenance and changeover costs, eliminates post-dispensing drippage, and provides a more efficient and dependable method for dispensing shots of flowable materials.